Audio systems typically require heat-sinks to dissipate heat energy generated by the amplification of audio channels. Multiple channels and high power levels are common in modern audio systems thus contributing to addition to the heat energy. Audio amplifiers contain current sensitive components whose temperature rises rapidly with excessive current consumption (e.g. bipolar devices can experience thermal runaway) and can cause irreparable damage to the audio system. Furthermore, peak power consumption occurs during transient events (e.g. playing audio at an unusually loud volume) but can require a heat sink that is both larger and heavier than required for typical operation of the audio system. A need exists to efficiently manage thermal energy consumption during these transient events without requiring an excessively large and heavy heat-sink and general system overdesign.
U.S. Pat. No. 4,939,786 discloses an adaptive thermal protection method and arrangement for a power amplifier by remote sense, which maximizes the amount of power from electronic equipment such as a radio frequency (RF) power amplifier, having a finite heat sink and operating intermittently over a period of time. This method and apparatus utilizes a remote temperature sensor and knowledge of the on/off, or key/dekey times in conjunction with a stored, predetermined thermal model to adjust the operating power level to a maximum permissible point within a range of operating power levels such that the projected temperature of the power amplifier does not exceed a preset limit. In so doing, the apparatus and method combines the advantages of thermal protection and power maximization and effects gradual changes in the operating power level by adapting to variable environmental and operational conditions. This system relies on knowledge of on/off keying durations and does not teach a solution to adaptive thermal management of continuous time audio systems. Thus, there remains a need for the efficient thermal management of audio systems.